Surfacing station for manufacturing optical elements and related manufacturing facility

ABSTRACT

There is provided a surfacing station for processing of surfaces of optical elements as workpieces, including a processing unit configured to process surfaces of optical elements; a controller unit configured to communicate with a database containing processing protocols, which can be carried out by the surfacing station, and to control operation of the processing unit in accordance with the processing protocols; and an identification tag base configured to communicate with the controller unit and configured to determine identification tags of consumable items used by the surfacing station, the controller unit being configured to enable a surfacing protocol for processing of the optical elements as workpieces in function of an identified consumable item.

FIELD OF THE INVENTION

The invention relates to a surfacing station, in particular a polishingstation for manufacturing optical elements like spectacle lensesaccording to a prescription and more generally to a relatedmanufacturing facility with different processing stations, in particularfor fine processing of optically effective surfaces.

BACKGROUND AND PRIOR ART

If in the following, by way of example, reference is made to “opticalelements”, in particular “spectacle lenses” for workpieces withoptically effective surfaces there is to be understood by that not onlyoptical elements of mineral glass, but also optical elements of allother customary materials such as polycarbonate, CR 39, HI index, etc.,thus also plastics material.

Processing of optically effective surfaces of spectacle lenses bymaterial removal can be roughly divided into two processing phases,namely initially preparatory processing of the optically effectivesurface for producing the macro-geometry in accordance with prescriptionand then fine processing of the optically effective surface in order toeliminate preparatory processing tracks and obtain the desiredmicro-geometry. Whereas preparatory processing of the opticallyeffective surfaces of spectacle lens is carried out in dependence on,inter alia, the material of the spectacle lenses by grinding, millingand/or turning. In fine processing the optically effective surfaces ofspectacle lenses are usually subjected to a precision-grinding, lappingand/or polishing process, for which purpose use is made of anappropriate machine.

To that extent, in the terminology of the present application the term“polishing”, including expressions such as, for example, “polishingtool” or the like is to embrace precision-grinding and lappingprocesses, in the example thus precision-grinding or lapping tools.

Manually loaded polishing machines in RX workshops, in particular, areusually constructed as “twin machines” so that advantageously twospectacle lenses of an “RX job”—a spectacle lens prescription generallyconsists of a pair of spectacle lenses—can be subjected to fineprocessing simultaneously. Such “twin” polishing machines are knownfrom, for example, documents DE 10 2009 041 442 A1 and DE 10 2011 014230 A1, which with respect to machine kinematics form the closest priorart.

According to, for example, the last-mentioned document (see, inparticular, FIGS. 1 to 5 thereof) such a polishing machine comprises amachine housing bounding a work space into which project two workpiecespindles, by way of which the two spectacle lenses to be polished can bedriven by means of a rotary drive to rotate about substantially mutuallyparallel workpiece axes of rotation C1, C2. On the tool side, thepolishing machine has a first linear drive unit by means of which afirst tool carriage is movable along a linear axis X extendingsubstantially perpendicularly to the workpiece axes of rotation C1, C2,a pivot drive unit which is arranged on the first tool carriage and bymeans of which a pivot yoke can be pivoted about a pivot setting axis Bextending substantially perpendicularly to the workpiece axes ofrotation C1, C2 and substantially perpendicularly to the linear axis X,a second linear drive unit which is arranged on the pivot yoke and bymeans of which a second tool carriage is movable along a linear settingaxis Z extending substantially perpendicularly to the pivot setting axisB, and two tool spindles each with a respective tool mounting section,wherein each of the tool mounting sections projects into the work spaceto be associated with a respective one of the workpiece spindles.

Each tool spindle has a spindle shaft on which the respective toolmounting section is formed and which is mounted in a spindle housing tobe driven to rotate about a tool axis of rotation A1, A2, which housingin turn is guided in a guide tube to be capable of defined axialdisplacement in the direction of the tool axis of rotation. Whereas thespindle housings of the two tool spindles are flange-mounted on thesecond tool carriage, the guide tubes are mounted on the pivot yoke sothat as a result the tool axis of rotation A1 or A2 of each tool spindleforms with the workpiece axis of rotation C1 or C2 of the associatedworkpiece spindle a plane in which the respective tool axis of rotationA1 or A2 is axially displaceable (linear axis X, linear setting axis Z)and tiltable (pivot setting axis B) with respect to the workpiece axisof rotation C1 or C2 of the associated workpiece spindle.

By virtue of the given possibilities of movement, the prior artpolishing machine allows—with a compact construction—pairwise processingof spectacle lenses by a so-called “tangential polishing kinematic” inwhich the polishing tools axially adjusted (Z) together with the toolspindles are moved under a preset, and fixed, pivot angle (B) of thetool spindles in oscillation with relatively small strokes transversely(X) over the spectacle lenses, but also with a polishing kinematic inwhich the adjusted (Z) polishing tools during the oscillating transversemovement (X) thereof at the same time continuously pivot (B) so as tofollow the surface curvature of the spectacle lenses, wherein thespectacle lenses and the polishing tools can be driven (but do not haveto be at least as far as the polishing tools are concerned) in the samesense or opposite sense at the same or different rotational speeds aboutthe axes of rotation (A1, A2, C1, C2) thereof.

However, in the case of specific materials which are difficult to polishsuch as, for example, polycarbonate materials or high-index material itis still desirable to process with different polishing bases in order toreduce polishing times and/or achieve specific surface qualities, whichin the afore-described prior art would require a change of polishingtools. The same applies if spectacle lenses to be polished in successionsignificantly differ in the geometry thereof (surface curvature,diameter). Tool change times thus required can indeed be significantlyreduced for industrial production by use of automated tool changers withtool magazines, but this would be involve a substantial outlay onequipment and investment costs.

In order to resolve this problem, the Applicant of the presentapplication has proposed in DE 10 2014 015 053 (hereby incorporated byreference) a polishing station allowing different processing strategieswithout requiring longer processing times.

According to DE 10 2014 015 053, the polishing station comprises

-   -   a workpiece spindle, which projects into a work space and by way        of which a workpiece to be polished is drivable for rotation        about a workpiece rotational axis C, and    -   two tool spindles which are associated with the workpiece        spindle and project oppositely into the work space and on each        of which a respective polishing tool is mounted to be drivable        for rotation about a tool rotational axis A, A′ and to be        axially adjustable along the tool rotational axis A, A′, the        tool spindles being movable relative to the workpiece spindle in        common along a linear axis extending substantially        perpendicularly to the workpiece rotational axis and being        pivotable about different pivot setting axes extending        substantially perpendicularly to the workpiece rotational axis        and substantially perpendicularly to the linear axis.    -   This polishing station is in particular interesting when        different polishing tools are used at the two tool spindles of        one device it is possible to carry out, for example, preparatory        polishing and fine polishing with different polishing slurry        carriers also known as polishing pads in one tool chucking,        which makes very short polishing times possible with, at the        same time, increased surface quality.

It is also possible, to increase the working range of the device by useof polishing tools of different size (tool diameter) and/or differentcurvature (tool radius of curvature) at the two tool spindles of onedevice. Thus, for example, very small or very large workpieces with, ina given case, strongly curved surfaces can be processed by the devicewithout a tool change having to be undertaken for that purpose, whichconsequently is helpful towards achieving shorter overall processingtimes.

However, the applicant has observed that the usage rate of suchpolishing stations, in particular in an automated manufacturing facilityis not optimized, in particular when one of the two polishing toolsassociated to one workpiece spindle is worn and needs to be replacedwhereas the other tool still may be used further on. This situation mayoccur frequently if the different polishing tools have differentlifetimes, in case the tool usage is different in function of the lensesto be polished (indeed, not all lens blanks need a preparatorypolishing) or a defect appears on one of the polishing tools. In thiscase, to avoid scrapping of lens blanks, the whole polishing station isstopped while waiting for a maintenance operation replacing the worn ordefect polishing tool.

This problem can be extended also to other surfacing stations thanpolishing stations like for example finishing stations for example foredging optical elements like spectacle lenses.

Therefore one object of the present invention is to improve the usagerate of surfacing stations like for example a polishing station inparticular when integrated in an automated manufacturing facility.

To this extent, the present invention proposes a surfacing station forprocessing of surfaces of optical elements as workpieces comprising:

-   a processing unit for processing surfaces of optical elements,-   a controller unit configured to communicate with a database    containing processing protocols which can be carried out by the    surfacing station, and controlling the operation of the processing    unit in accordance to the processing protocols,-   wherein the surfacing station further comprises an identification    tag base configured to communicate with the controller unit and    configured to determine identification tags of consumable items used    by the surfacing station, the controller unit being configured to    enable a surfacing protocol for processing of optical elements as    workpieces in function of the identified consumable item.

Thanks to the identification tag reader, a consumable item can beinstalled or supplied safely in the surfacing station and malfunctioningor a possibility of confusion can be avoided. In particular, thesurfacing station may configure itself by enabling only processingprotocols that are compatible with the consumable items installed.Furthermore, re-use of consumable items where the life-time has forexample not yet expired is possible.

The surfacing station according to the invention may comprise one orseveral of the following features taken alone or in combination:

According to one aspect, the identification tag contains data about thetype of the consumable item.

According to another aspect, the tag contains data about lifetime and/orquantity of the consumable item.

The identification tag may be a RFID tag or a barcode/matrix code tag.

The surfacing station may be a polishing station, the processingprotocol is for example a polishing protocol and the consumable itemcomprises at least one consumable item out of the following group ofconsumable items: a polishing disc of a polishing tool or a container ofpolishing slurry.

When the surfacing station is a polishing station as defined above,

the polishing station may comprise

i) a workpiece spindle, which projects into a work space and by way ofwhich a workpiece to be polished is drivable for rotation about aworkpiece axis of rotation,

ii) two tool spindles which are associated with said workpiece spindleand project oppositely into the work space and configured to support arespective polishing tool drivable for rotation about a tool axis ofrotation and axially adjustable along the tool axis of rotation,

the database containing at least one polishing protocol including atwo-step polishing process with different polishing medium carriers andat least one polishing protocol including a one-step polishing process.

According to a further aspect, the surfacing station may comprise a tagwriter configured to write life-time data to the identification tagallowing re-use of the consumable item if life-time of the consumableitem has not expired.

The controller unit is for example further configured to generate anoutput of enabled processing protocols for processing of opticalelements as workpieces.

According to one aspect, the data base contains for at least for onespecific job data a first two-step processing protocol and a secondone-step processing protocol of longer duration than the first two-stepprocessing protocol and leading to the same processing result and thecontroller unit is configured to switch from said first two-stepprocessing to said second one step processing in case the first two-stepprocessing protocol is disabled.

The present invention also relates to a manufacturing facility formanufacturing of optical elements comprising:

-   -   several surfacing stations as defined above,    -   a transfer system for conveyance of optical elements to be        processed according to specific job data,    -   a management system communicating with the controller units of        the surfacing stations and controlling the transfer system for        conveyance of the optical elements to be processed,    -   wherein the management system is configured to control the        transfer system to convey optical elements to be processed        according to specific job data to a surfacing station where the        enabled processing protocol(s) corresponds to the job data of        the optical elements to be processed.

According to one aspect, in case the surfacing station is a polishingstation, the management system may be configured

-   -   to analyze a predetermined number of job data of optical        elements to be processed,    -   to determine an optimized polishing tool configuration of the        pool of polishing stations, and    -   to generate an output for exchange of polishing tools within the        pool of polishing stations if the optimized polishing tool        configuration differs from the working polishing tool        configuration.

The present invention also relates to a polishing disc for a polishingtool for processing of surfaces of optical elements as workpieces for apolishing station comprising:

-   -   a base body which has a center axis and to which is secured an        intermediate layer, on which a polishing medium carrier rests,        of a resilient material,    -   an RFID tag configured to be read by the identification tag base        of the polishing station and including the type of the polishing        disc and life-time data,        wherein the RFID tag is integrated in the base body of the        polishing disc on the center axis.

The invention also relates to a method for operating a surfacing stationfor processing of surfaces of optical elements as workpieces as definedabove, comprising the following steps:

-   determining the information contained on the identification tag of    the consumable item,-   enabling processing protocol(s) for processing of optical elements    as workpieces in function of the identified consumable item.

According to one aspect, the identification tag is a RFID tag and themethod further comprises the step of writing life-time data to the RFIDtag allowing re-use of the consumable item if life-time of theconsumable item has not expired.

The invention also relates to a method for operating a manufacturingfacility for manufacturing of optical elements as defined abovecomprising a step of conveying optical elements to be processedaccording to specific job data to a surfacing station where the enabledprocessing protocol(s) corresponds to the job data of the opticalelements to be processed.

In case the data base contains for at least one specific job data afirst two-step processing protocol and a second one-step processingprotocol of longer duration than the first two-step processing protocoland leading to the same processing result, the method may comprisefurthermore the step of switching from said first two-step processing tosaid second one step processing in case the first two-step processingprotocol is disabled.

In case the surfacing stations are polishing stations, the method mayfurther comprise the steps of

-   -   analyzing a predetermined number of job data of optical elements        to be processed,    -   determining an optimized polishing tool configuration of the        pool of polishing stations, and    -   generating an output for exchange of polishing tools within the        pool of polishing stations if the optimized polishing tool        configuration differs from the working polishing tool        configuration.

BRIEF DESCRIPTIONS OF THE DRAWINGS

Other advantages and characteristics will appear with the reading of thedescription of the following figures:

FIG. 1 shows a simplified diagram of an example of a manufacturingfacility for manufacturing of optical elements like spectacle lensesaccording to the present invention,

FIG. 2 shows a simplified diagram of an example of a polishing stationas an example of a surfacing station according to the present invention,

FIG. 3 shows a longitudinal sectional view of the polishing stationwhich is identical to FIG. 6 of DE10 2014 015 053 (US2017/0246720),

FIG. 4 shows an example of a longitudinal section view of the front toolspindle, which is mounted in the front pivot yoke of the polishingstation, with a polishing tool, at the tool mounting head of which isdetachably mounted a polishing disc disposed in processing engagementwith a surface to be processed, wherein the polishing tool is disposedin a lower setting moved out (adjusting axis Z) relative to the toolspindle and the associated bellows have been omitted for simplificationof the illustration, FIG. 4 being nearly identical to FIG. 8 of DE102014 015 053 (US2017/0246720),

FIG. 5 shows a cross sectional view of an example of a polishing discaccording to the present invention,

FIG. 6 shows an example of a flow chart of a method for operating apolishing station for processing of surfaces of optical elements likespectacle lenses as workpieces, and

FIG. 7 shows an example of a flow chart of a method for operating amanufacturing facility for processing of optically effective surfaces ofspectacle lenses as workpieces.

DETAILED DESCRIPTION

The embodiment(s) in the following description are only to be consideredas examples. Although the description may refer to one or severalembodiments, this does not mean inevitably that every reference concernsthe same embodiment, or that the characteristics apply only to a singleembodiment. Simple characteristics of various embodiments can be alsocombined to new embodiments that are not explicitly described.

In the present description, the terms “upstream” and “downstream” areused according the following meaning: a first station for a certainprocessing operation of an optical element is placed upstream withrespect to a second station when the optical element undergoes first theoperation in the first station and then another operation in the secondstation.

And a first station for processing a certain processing operation of anoptical element is placed downstream with respect to a second stationwhen the optical element undergoes first the operation in the secondstation and then another operation in the first station.

By “surfacing”, it is understood in particular polishing, grinding, finegrinding or finishing and the overall object is to yield a finishedspectacle lens so that the curvature of the first (in this instanceconvex) face cx and the curvature of the machined second (in thisinstance concave) face cc cooperate to yield desired optical propertiesaccording to a prescription of the user of the spectacle lenses.

An optical element refers for example to an ophthalmic optical product,a lens blank or a semi-finished lens blank. The optical element maypresent or not an optical correction and may be used for as spectaclelens, in particular as sunglasses or masks.

The optical element may be formed of one layer or several layersattached to each other and forming a unitary element.

In FIG. 1 is shown a manufacturing facility 300 for manufacturing ofoptical elements as for example spectacle lenses L (see FIG. 4).

The manufacturing facility 300 comprises several surfacing stations, inthe present example realized as polishing stations 302, four in thepresent case.

In the present description, a polishing station 302 is described indetail as a possible example of a surfacing station for processing ofsurfaces of spectacle lenses. Therefore when referring to reference 302,it is referred to a surfacing station in general which encompasses apolishing station 302 in particular, but also for example a finishingstation configured to edge for example already coated spectacle lenses.

The manufacturing facility 300 may also comprise other not shownprocessing stations like blocking stations disposed upstream thepolishing stations 302 or washing stations, tunnel ovens, coatingstations, deblocking stations, or finishing stations disposed downstreamthe polishing stations 302.

The manufacturing facility 300 further comprises a transfer system 304for conveyance of optical elements to be processed according to specificjob data.

In FIG. 1 are shown different conveyors 306 among which also a loopconveyor 306-L. The conveyors 306, 306-L link different processingstations and are in particular in FIG. 1 linked to the polishingstations 302 to supply optical elements like lens blanks to be polishedor surfaced and to convey polished optical elements to furtherprocessing stations for example for coating.

The optical elements as for example lens blanks are transported intransportation trays 308 which circulate in the transfer system 304.

The manufacturing facility 300 also comprises a management system 310with a display and control panel 312. The management system 310 maycomprise computers, processors and memories as well as software forcontrolling the whole manufacturing process of the optical elements L.

The management system 310 communicates with the different processingstations, in particular with polishing stations 302 and controls thetransfer system 304 with its conveyors 306, 306-L.

The management system 310 also receives job data for each spectacle lensL to be manufactured. Each transportation tray 308 contains in generaltwo lens blanks to be processed and is specifically identified forexample by a tray identification tag. Such tray identification tag maybe a RFID tag or a barcode/matrix code. Different tag readers aredisposed in the transportation system 304, in particular along conveyors306, 306-L and allow localizing and directing the transportation trays308 within the manufacturing facility 300. Thus, the management system310 is configured to route the transportation trays 308 between thedifferent processing stations.

Furthermore, each tray identification tag is associated with job datafor processing the lens blanks contained in the associatedtransportation tray 308 in order to obtain final lenses that are inconformity with a prescription and wishes of a user, in particular theprescribed optical correction power and specific treatments applied tothe lenses according to the wishes of the user in order to enhance forexample the vision comfort of the user and to protect the opticalelements against aggressions like for example scratches, dust andsoiling materials.

An example of a surfacing station as polishing station 302 according thepresent invention will now be described with reference to FIGS. 2-5.Concerning many aspects, in particular mechanical construction, thepolishing station 302 may be similar to that disclosed in DE10 2014 015053 (US2017/0246720) incorporated by reference.

However, the present invention is not limited to such a polishingstation 302 and may be applied to simpler polishing stations or othersurfacing stations like finishing stations.

As shown schematically in FIG. 2, the polishing station 302 comprisesthree processing units realized in the present example as polishingcells 10, 10′, 10″ of respectively identical construction.

In the present description, a polishing cell will be described in detailas a possible example of a processing unit for processing of surfaces ofoptical elements. Therefore when referring to references 10, 10′, 10″,it is referred to a processing unit in general which encompasses apolishing cell 10, 10′ or 10″ in particular, but also for example aprocessing unit in a finishing station configured to edge for examplealready coated optical elements.

Polishing station 302 furthermore comprises a controller unit 200.

This controller unit 200 comprises for example a processor and memories(for example a PC) and is charged with adequate software to run thepolishing station in particular each of the polishing cells 10, 10′,10″.

The controller unit 200 is further configured to communicate with adatabase 202 of processing protocols (=polishing protocols in the caseof a polishing station).

In the present description, it is referred to a polishing protocol inparticular as a possible specific example of a processing protocol.Therefore when referring to a polishing protocol, it is referred to aprocessing protocol in general which encompasses a polishing protocol inparticular, but also for example a processing protocol of a finishingstation configured to edge for example already coated optical elements.

A processing protocol (=polishing protocols in the case of a polishingstation) may be carried out by the surfacing station 302. This database202 may be a part of the memories of the controller unit 200 asrepresented in FIG. 2 but may also be located outside the surfacingstation 302, for example on a server or within the management system310.

A surfacing protocol is a series of instructions, in particular in caseof a polishing protocol for example kinematic movements, for polishing alens blank in order to achieve at least some of the desired opticalproperties of the lens L.

In particular, a polishing protocol may contain instructions to realizea first a preparatory polishing step on a lens L and then, secondly, afine polishing step. This case is referred to as two-step protocol.

A one-step protocol refers to the case when only a fine polishing stepis applied.

The polishing protocols in database 202 can be in particular one-step ortwo-step polishing protocols. Usually the database 202 will contain alarger amount of polishing protocols which can be a combination ofspecific one- and two-step polishing protocols.

Such polishing protocols are adapted and optimized with respect to jobdata information for manufacturing of optical elements in particularlens material and desired subsequent coating in order to reducemanufacturing time while ensuring highest quality standards.

For example database 202 may comprise at least one polishing protocolincluding a two-step polishing process with different polishing pads orpolishing medium carriers and at least one polishing protocol includinga one-step polishing process.

The controller unit 200 is further configured to control the operationof the polishing cells 10, 10′, 10″ in accordance to the polishingprotocols and also taking into account the job data of the lenses to bemanufactured (optical power, curvatures, lens material, etc.).

The controller unit 200 is for example further configured to enable ordisable specific features of the polishing station 302 in function ofthe determined identification tag 206, concerning for example monitoringfeatures.

The polishing station 302 further comprises an identification tag base204 (for example an identification tag reader) configured to communicatewith controller unit 200 of the polishing station 302 and configured todetermine information, for example by reading, on identification tags206 (RFID tag or a barcode/matrix code tag) of consumable items 208(like a polishing discs 106, 106′ in FIG. 3) used by the polishingstation 302.

When supplying a consumable item 208 to polishing station 302 like forexample a polishing disc 106 or a container of polishing slurry (notshown), an operator passes the consumable item 208 in front of theidentification tag base 204 which may be installed near a control anddisplay panel 209. The information on the identification tag 206 isdetermined and sent to the controller unit 200 which can adapt thefunctioning of the polishing station 302 in accordance to the installedconsumable items 208, in particular by enabling or not a polishingprotocol for processing of optical elements as workpieces and/orenabling or disabling specific features of the polishing station 302.

The identification tag 206 contains data about the type of theconsumable item for example a polishing disc 106 and for which type ofpolishing the polishing disc 106 is suited (for example universalpolishing, preparatory polishing, fine polishing etc.). The type of theconsumable item 208 may be related to specific polishing protocols indatabase 202. The identification tag may also comprise information aboutthe manufacturer, the production date etc. This information may also berelated to specific features or functions of the polishing station 302that may be enabled or not dependent on the information contained in theidentification tag 206.

The identification tag 206 may further contain directly or indirectlyinformation about the life-time and/or quantity of the consumable item208.

For example, when, after respective identification tags 206 beingdetermined, in one polishing cell 10 are installed a first polishingdisc 106 for preparatory polishing or grinding and a second polishingdisc 106′ for fine polishing, the controller unit 200 enables for thispolishing cell 10 one polishing protocol for one-step polishing (onlyfine polishing) and one polishing protocol for two-step polishing(preparatory polishing or grinding followed by fine polishing).

Assuming after some time, the first polishing disc 106 for preparatorypolishing or grinding 106 is worn out because its life-time is over,then the controller unit 200 disables the polishing protocol fortwo-step polishing (preparatory polishing followed by fine polishing).However, the polishing cell 10 can still continue to function but onlyfor jobs requesting the polishing protocol for one-step polishing (onlyfine polishing).

In this context, enabling or not a processing protocol is not mereblocking of the processing of the station or not.

For example if after respective identification tags 206 beingdetermined, in one polishing cell 10 are installed a first polishingdisc 106 for preparatory polishing or grinding and a second polishingdisc 106′ for fine polishing, the controller unit 200 enables for thispolishing cell 10 several processing protocols as stated above, some ofthem being even equivalent in its final result.

For example for a specific job, the curvature and surface propertiesmight be achieved for a specific lens by a two-step protocol(preparatory polishing followed by fine polishing), but also by aone-step protocol (only fine polishing, but a longer time).

Both processing protocols are equivalent with regard to the achievedresult, but the duration of the two-step protocol is for example lessthan the duration of the equivalent one-step protocol. The movements inthe two equivalent protocols may also be different.

In manufacturing this is an important advantage because in case that thefirst polishing disc 106 for preparatory polishing is worn out, thestation might continue by switching from the two step protocol to itsequivalent one-step protocol with a lower throughput.

Thus one understands that tools, in particular a first and a secondtool, might enable different processing protocols leading to the sameend result and that therefore the use of the tools and the stationitself can be optimized in function of upcoming jobs.

The controller unit 200 is further configured to generate an output ofenabled polishing protocols for processing of optical elements, whichoutput is sent to the management system 310.

The management system 310 is further configured to control the transfersystem 304 to convey optical elements as for example lens blanks to beprocessed according to specific job data only to a polishing station 302where the enabled polishing protocol(s) corresponds to the job data ofthe optical elements to be processed.

This allows also to prevent malfunctioning of the polishing station 302for example in case an operator installs accidently in one polishingcell 10 two second polishing discs 106′ for fine polishing instead oftwo different polishing discs 106, 106′, one for preparatory polishingand one for fine polishing. In this case, the polishing cell 10 canstill function but only for jobs requesting the polishing protocol forone-step polishing (only fine polishing).

In addition, this allows also extending the functional range andfeatures of the polishing station 302.

Indeed, a customer can buy a polishing station 302 with such a database202 of polishing protocols in a first time only for use of one-steppolishing protocols. In buying later on for example specific polishingdiscs 106, 106′, he may access to other polishing protocols allowing forexample two-step polishing or other specific polishing steps. Inenabling for example equivalent polishing one-step and two-stepprotocols, the throughput of the polishing station 302 may be enhanced.

Furthermore, one may adapt and optimize the utilization rate of thepolishing station 302.

Indeed, the management system 310 of the manufacturing facility 300 isfor example configured

-   -   to analyze a predetermined number of job data of optical        elements to be processed,    -   to determine an optimized polishing tool configuration of the        pool of polishing stations 302, and    -   to generate an output for exchange of polishing discs 106,106′        within the pool of polishing stations 302 if the optimized        polishing tool configuration differs from the working polishing        tool configuration.

This may be simply illustrated by a simple example.

Assuming all four polishing stations 302 of the pool are equipped withspecific “two” one-step-polishing discs 106 and in analyzing theupcoming job data, it turns out that the installed specificone-step-polishing discs are not suited for at least some of the opticalelements to be manufactured and listed in the upcoming job data becausetheir manufacturing process needs polishing discs of different size(tool diameter) and/or different curvature (tool radius of curvature)and/or different polishing slurry carriers.

Then the management system 310 can determine for example the number ofpolishing stations 302 that will be let unchanged and the number ofpolishing stations 302 that need to be equipped with new or differentpolishing discs, for example of different size. Preferentially, for thechange of the polishing discs 106, 106′, the management system 310 willselect the polishing station 302 (or polishing cell(s) 10, 10′, 10″)where the polishing discs 106, 106′ are near to be worn.

The output is for example displayed on a display and control panel 312of the management system 310 to inform an operator in service who canthen take the necessary steps to exchange the polishing discs 106, 106′in the indicated polishing stations 302 by scanning the consumable item208 to be exchanged or replaced first in front of the identification tagreader 204.

Therefore, the manufacturing facility 300 can continue manufacturingwith an optimized throughput.

Moreover, the identification tag reader 204 may also be a tag writerallowing registering of new information on the identification tag 206,like for example remaining life-time and other relevant information.

This allows for example re-use of the polishing disc 106, 106′ when thelife-time has not completely expired.

An example of the polishing cells 10, 10′ and 10″ is now described morein detail. As already stated, one polishing cell 10 is here disclosed asan example of a processing unit for processing surfaces of opticalelements. Such a processing unit may carry out other processing stepsthan polishing like for example edging.

Each polishing cell 10, 10′, 10″ comprises a workpiece spindle 14 whichprojects into a work space 13 and by way of which a spectacle lens L tobe polished, which is usually held by means of a blocking material M ona block piece S for mounting in the workpiece spindle 14 (see FIG. 4),can be driven to rotate about a workpiece axis of rotation C. Inaddition, the polishing cell 10 comprises two tool spindles 16, 16′,which are associated with the workpiece spindle 14 and projectoppositely into the work space 13 and on each of which a respectivepolishing tool 18, 18′ is mounted to be drivable for rotation about atool axis of rotation A, A′ and to be axially adjustable along the toolaxis of rotation A, A′ (adjusting axes Z, Z′). The tool spindles 16, 16′are movable relative to the workpiece spindle 14 in common along alinear axis X extending substantially perpendicularly to the workpieceaxis of rotation C and are pivotable about different pivot setting axesB, B′, which extend substantially perpendicularly to the workpiece axisof rotation C and substantially perpendicularly to the linear axis X. Inthat case, the tool spindles 16, 16′ are arranged one behind the otheras seen in the direction of the linear axis X.

According to FIG. 2 the individual polishing cells 10, 10′, 10″, whichare operable independently of one another, are so arranged in compactmanner adjacent to one another in modular form—and optionally to beseparately exchangeable as a respective module.

Within the polishing station 302, the transportation trays 308 with thelens blanks to be processed may be received and the lens blanks may betransferred automatically, for example by not shown portal handlingsystem to any of the polishing cells and back to the transportation tray308 after processing. Reference is made to DE10 2014 015 053(US2017/0246720) describing such a portal handling system.

In particular, after the processing by polishing, the spectacle lens Lpolished to finished state can be transported to an integrated not shownwashing unit 20 (schematically represented on FIG. 2) for removal ofpolishing medium residues by washing.

For further description of the polishing cell 10, the work space 13 ofthe polishing cell 10 is surrounded by a frame 36 which can beconstructed as, for example, a welded construction of steel parts.Upwardly, the work space 13 can be covered by a bellows-like work spacecover 38 and is closable at the front by a sliding door 39. In order toopen the work space 13 for access from outside, the work space cover 38,which is suitably guided laterally, can be displaced or retracted bymeans of a pneumatic cylinder 40.

In addition, a pneumatic cylinder 41 is provided for movement of thelaterally guided sliding door 39 and is suitably pivotably connectedbetween the sliding door 39 and the frame 36. Downwardly, the work space13 is bounded by a trough 42, which is deep-drawn integrally from aplastics material and which is suitably fastened to the frame 36, withstep-free wall surfaces and a receiving opening 43 for the workpiecespindle 14 (cf. FIG. 3), through which trough 42 the workpiece spindle14 extends—suitably sealed at the circumference—from below so as toproject into a lower region of the work space 13.

In FIG. 3, there can also be seen a drain opening 44 for the liquidpolishing medium. With respect to FIG. 3, the polishing cell 10 may beinstalled in a tilted position such that drain opening 44 is disposed atthe deepest point of the trough 42 in the state in which the polishingcell 10 is mounted.

The frame 36 has a base plate 45 at which the workpiece spindle 14 isflange-mounted below the receiving opening 43 in the trough 42 fromabove. At its end projecting into the work space 13 the workpiecespindle 14 has a collet chuck 46 which can be actuated by way of anactuating mechanism (not illustrated in more detail) so as to clamp aspectacle lens L, which is blocked on a block piece S, to the workpiecespindle 14 to be axially fixed and capable of rotational entrainment. Apneumatic cylinder, which is fastened below the base plate 45, for thesaid actuating mechanism is denoted by 47 (cf. FIG. 3), by means ofwhich the collet chuck 46 can be opened and closed in a manner known perse.

A rotary drive 48—in the illustrated embodiment a speed-controlledasynchronous three-phase motor—is flange-mounted from below on the baseplate 45. The rotary drive 48—similarly below the base plate 45—isdrivingly connected by means of a cogged belt drive 49 with theroller-bearing-mounted spindle shaft of the workpiece spindle 14 so thatthe rotary drive 48 is capable of rotationally driving the workpiecespindle 14 at a predetermined rotational speed and with a predetermineddirection of rotation (workpiece axis of rotation C).

A tool carriage 50 which is guided with respect to the frame 36 to bedrivable along the linear axis X is provided above the workpiece spindle14 for movement in common of the tool spindles 16, 16′. More precisely,provided for movement and positioning of the tool carriage 50, which isguided at two parallel guide rods 51 connected with the frame 36, is arotary drive (not shown) which is mounted on the frame 36 in fixedlocation and which is drivingly connected with a ball screw drive (notshown).

The tool carriage 50 has a frame construction with an inner opening 60,which is substantially rectangular for receiving the two pivotable toolspindles 16, 16′. In that case one, i.e. front, tool spindle 16 ismounted on or in a front pivot yoke 61, which is pivotably connectedwith the tool carriage 50 on either side of the opening 60 to be capableof defined pivotation about one pivot setting axis B, and the other toolspindle 16′ is mounted on a rear pivot yoke 62, which is pivotablyconnected with the tool carriage 50 behind the front pivot yoke 61 to becapable of defined pivotation about the other pivot setting axis B′again on either side of the opening 60.

A further linear drive 65 is provided for drive of the pivot yokes 61,62, i.e. for defined pivotation in common of the two tool spindles 16,16′ about the pivot setting axes B, B′ and is pivotably connected by oneend thereof with the front pivot yoke 61 at a spacing from thecorresponding pivot setting axis B and by the other end thereof with thetool carriage 50.

More specifically, in the illustrated embodiment the linear drive 65 isa proprietary so-called “electrocylinder” with an actuating rod 66 whichcan be moved in and out by way of a rotary drive 67 and a transmission68 in the case of corresponding energization of the rotary drive 67. Ifthe rotary drive 67 is not energized, self-locking is present in thetransmission 68, i.e. the actuating rod 66 remains in its respectiveinitial setting in the case of non-excessive external forces; anintegrated measuring system can feed back the respective position. Thislinear drive 65 is pivotably mounted at its end at the drive side on amounting fork 69 mounted on the tool carriage 50, whereas at the otherend of the linear drive 65 the actuating rod 66 pivotably engages aforked pivot arm 70 secured to the front pivot yoke 61.

For transmission of the pivot movement from the front pivot yoke 61 tothe rear pivot yoke 62 the two pivot yokes 61, 62 are in driveconnection by way of a coupling rod 71 which is spaced from the pivotsetting axes B, B′, in particular above the latter by one end thereof atthe front pivot yoke 61 and by the other end thereof at the rear pivotyoke 62.

In that respect it is apparent that in the case of the chain ofpivotation formed as described above a defined axial movement out ormovement in of the actuating rod 66 has the consequence that the pivotyokes 61, 62 are pivoted in defined manner about the pivot setting axesB, B′, whereby the tool spindles 16, 16′, which are arranged centrallyin the respective pivot yoke 61 or 62, are pivoted while remaining inparallel orientation relative to one another.

Further details with respect to the tool spindles 16, 16′ can beinferred from FIG. 4, which by way of example show, for the twoidentically constructed tool spindles 16, 16′ coupled to the respectivepivot yoke 61, 61, the front tool spindle 16 (also) in section.

The tool spindle 16 comprises a spindle housing 74, by way of which thetool spindle 16 according to FIG. 4 is flange-mounted from below on thepivot yoke 61. The dot-dashed lines shown in FIG. 4 indicate a screwconnection. The further components or subassemblies of the tool spindle16 are rotatably mounted in the spindle housing 74 by way of a bearingarrangement of roller bearings comprising a lower fixed bearing 75 andan upper floating bearing 76, which are mounted in the spindle housing74 at a spacing from one another by means of a spacer bush 77.

Each tool spindle 16, 16′ has a piston-cylinder arrangement 78, 78′(also indicated in FIG. 3) for axial adjustment (adjusting axes Z, Z′)of the respective polishing tool 18, 18′ along the associated tool axisof rotation A, A′. The piston-cylinder arrangement 78 has a piston 80which is received in a cylinder housing 79 and which is connected, to beeffective in terms of actuation, in coaxial arrangement with a spindleshaft 81 movable out of the spindle housing 74 in accordance with FIG.4. For movement of the spindle shaft 81 out of the spindle housing 74the piston-cylinder arrangement 78 can be acted on pneumatically by wayof a proprietary rotary transmission leadthrough 82, 82′ at the end ofthe cylinder housing 79 at the top in the figures. In that case, thepiston-cylinder arrangement 78 together with the spindle shaft 81 isrotatable in the spindle housing 74 about the tool axis of rotation A,as already indicated.

The cylinder housing 79 is, in addition, of two-part construction with ahousing upper part 83 and a housing lower part 84, which arescrew-connected together centered relative to one another at 85. In thatregard, received in the interior for lining the cylinder housing 79 is aguide sleeve 86 of mineral glass which is secured in the housing upperpart 83 with the assistance of an O-ring 87 and in which the piston 80,which consists of a graphite material at its guide surface, is receivedto be longitudinally displaceable. “Glass cylinders” of that kind, whichare very easy-running and substantially free of stick-slip, arecommercially available from, for example, the company AirpotCorporation, Norwalk, Conn., United States. In order to avoid jamming,which can result from axial alignment errors in the (ideally) coaxiallyarranged components, the piston 80 of the piston-cylinder arrangement 78is tension-resistantly and compression-resistantly connected with thespindle shaft 81 by way of a thin rod 88 of spring steel and, inparticular, by way of the screw connections shown in FIG. 4 at the topand bottom at the rod 88.

The housing lower part 84 of the cylinder housing 79 is rotatablysupported by way of the floating bearing 76 in radial direction on thespindle housing 74 at the top in the figures. At the bottom in thefigures, a labyrinth member 89 is flange-mounted on the housing lowerpart 84 by means of a screw connection 90 which in that case togetherwith the housing lower part 84 axially clamps the inner ring of thefixed bearing 75 in place. The labyrinth member 89 forms, as the nameitself indicates, together with the underside of the spindle housing 74at 91 a sealing labyrinth with narrow gap dimensions and additionallyhas radially within the sealing labyrinth 91 an annular recess 92 forreception of a sealing ring 93, the sealing lip of which similarlysealably co-operates with the lower side of the spindle housing 74.

As FIG. 4 shows, the housing upper part 83 of the cylinder housing 79passes through an opening 94 formed in the pivot yoke 61 and projectsupwardly above this in FIG. 4. The housing upper part 83 of the cylinderhousing 79 is there provided at the outer circumference with a toothing95 for engagement by a cogged belt 96. The cogged belt 96 is drivable byway of a motor 97—which is flange-mounted from above on the pivot yoke61 and is similarly of identical construction for each pivot yoke 61,62—with a belt pulley 98 so as to rotate the piston-cylinder arrangement78 and thus the spindle shaft 81 in the spindle housing 74 controllablyin rotational speed and rotational direction about the tool axis ofrotation A.

In addition, provided for torque transmission from the thus-rotatingdrivable cylinder housing 79 of the piston-cylinder arrangement 78 tothe spindle shaft 81 is a splined shaft guide 99 with guide grooves 100,which are formed in the spindle shaft 81, and a flange nut 102, which isin engagement therewith by way of an axial bearing element 101—since itis known per se, it is indicated in FIG. 4 merely by a thick line—andwhich is received in the labyrinth member 89 and flange-mounted thereonby means of a screw connection 103, so that the flange nut 102 isconnected with the cylinder housing 79 to be secure against relativerotation. Splined shaft guides of that kind are commercially availablefrom, for example, the company Nippon Bearing Co Ltd, Ojiya-City, Japan.

To that extent it is evident that the spindle shafts 81 of the toolspindles 16, 16′ are drivable—controllably in rotational speed androtational direction—at a given time independently of one another forrotation about the tool axes of rotation A, A′ and/or adjustableindependently of one another along the tool axes of rotation A, A′, in agiven case also with very fine sensitivity (adjusting axes Z, Z′).

Details with respect to the polishing tool 18, which is currentlypreferred for use in this polishing cell 10, can similarly be inferredfrom FIG. 4. According to that, the tool spindle 16, 16′ have a toolmounting head 104 with a mounting plate 105 which is secured to thespindle shaft 81 of the tool spindle 16 to be capable of axial androtational entrainment and at the same time to be detachable.

A polishing disc 106 which is considered here as a consumable item, isexchangeable mounted on the tool mounting head 104, for which purpose abase body 107 of the polishing disc 106 and the tool mounting head 104,more precisely the mounting plate 105 thereof, are provided withcomplementary structures 108 for axial detenting and rotationalentrainment of the polishing disc 106 by the tool mounting head 104.

This interface, which is formed by the complementary structures 108,between polishing disc 106 and tool mounting head 104 is the subject ofdocument EP 2 464 493 B1, to which, for avoidance of repetitions,express reference may be made at this point with regard to constructionand function of the interface.

On the side of the mounting plate 105 remote from the polishing disc 106the tool mounting head 104 has a ball joint 109 with a ball head 111which is received in a ball socket 110 and which is constructed at aball pin 112 securable to the spindle shaft 81 of the tool spindle 16,more precisely able to be screwed in at the end thereof. On the otherhand, the ball socket 110 is formed in the mounting plate 105 with whichthe polishing disc 106 is detentable. In the illustrated embodiment theball head 111 has a receiving bore 113 for a transverse pin 114, whichextends through the ball head 111 by radiused ends and engages on eitherside of the bore head 111 in associated recesses 115 in the ball socket110 so as to connect the mounting plate 105 in the manner of a universaljoint with the ball head 111 and thus with the spindle shaft 81 of thetool spindle 16 to be capable of rotational entrainment.

In addition, a circularly annular support flange 116 is introducedbetween the ball pin 112 and the free end of the spindle shaft 81 and issecured to the spindle shaft 81 by means of the ball pin 112. Aresilient annular element 117 consisting of, for example, a suitablefoam material rests on the support flange 116, by way of which annularelement the mounting plate 105 of the tool mounting head 104 can beresiliently supported on the support flange 116 at the ball pin side insuch a manner that the polishing disc 106 detented with the mountingplate 104 seeks to self-align by its center axis with the ball pin 112and thus the spindle shaft 81 of the tool spindle 16.

In addition, it can be seen in FIG. 4 that the tool mounting head 104 inan axially retracted setting of the spindle shaft 81 can be detentedwith the labyrinth member 89—as a part connected with the cylinderhousing 79 to be secure against relative rotation—by means of a detentdevice 118. The detent device 118 has a plurality of spring projections119, which are distributed around the circumference of the tool mountinghead 104 and protrude along the tool axis of rotation A and which are inmechanically positive engagement with lugs 120 in an annular groove 121formed at the labyrinth member 89. The polishing tool 18 can thus bemounted without force by detenting in a retracted setting at the toolspindle 16. For recognition of the moved-up position of the polishingtool 18—and thus a tool loading position of the tool spindle 16—anannular magnet RM is glued in place in the piston 80 of thepiston-cylinder arrangement 78 and co-operates with a magnet sensor MS(see FIG. 3) in the vicinity of the rotary transmission lead-through 82.

As also shown in FIG. 5, an intermediate layer 122, which is softer bycomparison with the base body 107 and on which a polishing mediumcarrier 123 rests, of a resilient material is secured to the base body107 of the polishing disc 106 illustrated here, the polishing mediumcarrier 123 forming the actual outer processing surface 124 of thepolishing disc 106. This design of the polishing disc 106 is to thatextent special, since the intermediate layer 122 has at least tworegions of different hardness which are arranged one behind the other inthe direction of the center axis of the polishing disc 106, wherein theregion of the intermediate layer 122 adjoining the base body 107 issofter than the region of the intermediate layer 122 on which thepolishing medium carrier 123 rests. More precisely, the two regions ofthe intermediate layer 122 are here formed by mutually different foammaterial layers 125, 126 of respectively constant thickness as seenalong the center axis of the polishing disc 106, namely a softer foammaterial layer 125 on the base body 107, more precisely the sphericalend surface 127 thereof, and a harder foam material layer 126 under thepolishing medium carrier 123. The entire tool concept as such is alsodescribed in DE 10 2014 015 052.6 (US 2017/0246729 A1) incorporated byreference.

In that case, the individual components (107, 125, 126, 123) of thepolishing disc 106 are glued together. This polishing disc 106 isuniversally usable for a wide range of workpiece curvatures, inparticular the actual construction and dimensioning thereof.

Other polishing tools or polishing discs can obviously also be used withthe polishing cell 10 in correspondence with the respective polishingrequirements.

The different polishing processes able to be performed according to apolishing protocol by the afore-described kinematics of the polishingcell 10—in which moreover a liquid polishing medium is supplied to thepoint of action between tool and workpiece by way of polishing mediumnozzles 128 provided at the workpiece spindle 14 (see FIG. 3) arewell-known to the expert and therefore shall not be described in moredetail at this point.

Turning now more specifically to FIG. 5 showing more in detail a crosssectional view of a polishing disc 106.

As already stated, a polishing disc 106 can be considered as aconsumable item for a polishing station 302. Indeed, polishing discshave a limited life-time and need to be changed regularly when worn out.

Furthermore, there exist different types of polishing discs 106 that canbe used in a polishing station 302 as described above, for example onefor preparatory polishing and one for fine polishing with differentpolishing coatings. In this case, a two-step polishing is achieved inrealizing first a preparatory polishing with a first polishing disc 106having preparatory polishing properties and supported by polishing tool18 and a second polishing disc 106′ having fine polishing properties andsupported by polishing tool 18′ (see FIG. 3).

The polishing disc 106 in the present invention differs from thepolishing disc disclosed in EP 2 464 493 B1 by the fact that itcomprises in addition an identification tag 206.

The identification tag 206 may be a matrix code or bar code, but in thepresent case is a RFID tag 132.

This RFID tag 132 comprises in a known way means for communication witha RFID tag reader/writer 204 of the polishing station 302 (see FIG. 2).

In order to ward off any balancing problem of the polishing disc 106during rotation, in particular vibrations, the RFID tag 132 isintegrated in the base body 107 of the polishing disc 106 on the centeraxis D around which it rotates in functioning.

As shown on FIG. 6, the present invention also relates to a method foroperating a surfacing station, in particular a polishing station 302,comprising the following steps:

-   determining, for example by reading, S1 the information contained on    the identification tag 206 of the consumable item 208,-   enabling S2 processing, in particular polishing protocol(s) for    processing of optical elements as workpieces in function of the    identified consumable item 208.

In a further development allowing re-use of consumable items 208, forexample where the life-time has not yet completely expired, life-timedata may be written in a step S3 to the identification tag 206 allowingre-use of the consumable item 208.

With regard to FIG. 7, the present invention further relates to a methodfor operating a manufacturing facility 300 comprising in particular thestep S10 of conveying optical elements to be processed according tospecific job data to a surfacing station, in particular a polishingstation 302 where the enabled processing protocol(s), in particularpolishing protocol(s) corresponds to the job data of the opticalelements to be processed.

In a further development concerning polishing stations as surfacingstations, the method may comprise the steps of

-   -   analyzing S12 a predetermined number of job data of optical        elements to be processed,    -   determining S14 an optimized polishing tool configuration of the        pool of polishing stations, and    -   generating S16 an output for exchange of polishing tools 106        within the pool of polishing stations if the optimized polishing        tool configuration differs from the working polishing tool        configuration.

One therefore understands that the polishing stations 302 according tothe invention allow a safer use by avoiding malfunction in case aninattentive or distractive operator does not install the correctconsumable item 208. Furthermore, the capacities and functions of thesurfacing station, in particular polishing station 302 may evolve infunction of the installed consumable items 208, for example polishingdiscs 106, 106′. Reuse of not completely worn out consumable item is nowpossible in a safe manner. The throughput of a manufacturing facility300 may be optimized and manufacturing costs and delivery times arereduced.

REFERENCE NUMERAL LIST

-   -   10, 10′, 10″ processing unit (=polishing cell as example)    -   13 work space    -   14 workpiece spindle    -   16, 16′ tool spindles    -   18, 18′ polishing tool    -   20 washing station    -   36 frame    -   38 work space cover    -   39, 39′, 39″ sliding door    -   40 pneumatic cylinder    -   41 pneumatic cylinder    -   42 trough    -   43 receiving opening    -   44 drain opening    -   45 base plate    -   46 collet chuck    -   47 pneumatic cylinder    -   48 rotary drive    -   49 cogged belt drive    -   50 tool carriage    -   51 guide rod    -   60 opening    -   61 front pivot yoke    -   62 rear pivot yoke    -   65 linear drive    -   66 actuating rod    -   67 rotary drive    -   68 transmission    -   69 mounting fork    -   70 pivot arm    -   71 coupling rod    -   74 spindle housing    -   75 fixed bearing    -   76 floating bearing    -   77 spacer bush    -   78, 78′ piston-cylinder arrangement    -   79 cylinder housing    -   80 piston    -   81 spindle shaft    -   82, 82′ rotary transmission lead through    -   83 housing upper part    -   84 housing lower part    -   85 screw connection    -   86 guide sleeve    -   87 O-ring    -   88 rod    -   89 labyrinth member    -   90 screw connection    -   91 sealing labyrinth    -   92 annular recess    -   93 sealing ring    -   94 opening    -   95 toothing    -   96 cogged belt    -   97 motor    -   98 belt pulley    -   99 splined shaft guide    -   100 guide groove    -   101 axial bearing element    -   102 flange nut    -   103 screw connection    -   104 tool mounting head    -   105 mounting plate    -   106, 106′ polishing disc    -   107 base body    -   108 complementary structures    -   109 ball joint    -   110 ball socket    -   111 ball head    -   112 ball pin    -   113 receiving bore    -   114 transverse pin    -   115 recess    -   116 support flange    -   117 resilient annular element    -   118 detent device    -   119 spring projection    -   120 lug    -   121 annular groove    -   122 intermediate layer    -   123 polishing medium carrier    -   124 processing surface    -   125 softer foam material layer    -   126 harder foam material layer    -   127 end surface    -   128 polishing medium nozzle    -   132 RFID tag    -   200 controller unit    -   202 database of polishing protocols    -   204 identification tag base (for example tag reader and/or tag        writer)    -   206 identification tag    -   208 consumable item    -   209 control and display panel    -   300 manufacturing facility    -   302 surfacing station (=polishing station as example)    -   304 transfer system    -   306, 306-L conveyors    -   308 transportation trays    -   310 management system    -   312 display and control panel    -   A rotational axis of front polishing tool (open loop controlled        in rotational speed)    -   A′ rotational axis of rear polishing tool (open loop controlled        in rotational speed)    -   B pivot setting axis of front polishing tool    -   B′ pivot setting axis of rear polishing tool    -   C workpiece rotational axis (open loop controlled in rotational        speed)    -   D center axis of polishing disc    -   cc second optically effective surface (concave)    -   cx first optically effective surface (convex)    -   L optical element (for example a spectacle lens)    -   M blocking material    -   MS magnet sensor    -   RM annular magnet    -   S block piece    -   X linear axis of tool carriage (closed loop controlled in        position)    -   Z adjusting axis of front polishing tool (uncontrolled)    -   Z′ adjusting axis of rear polishing tool (uncontrolled)    -   S1, S2, S3 steps of a method for operating a polishing station    -   S10, S12, S14, S16 steps of a method for operating a        manufacturing facility for manufacturing optical elements

1.-17. (canceled)
 18. A surfacing station for processing of surfaces ofoptical elements as workpieces, comprising: a processing unit configuredto process surfaces of optical elements; a controller unit configured tocommunicate with a database containing processing protocols, which canbe carried out by the surfacing station, and to control operation of theprocessing unit in accordance with the processing protocols; and anidentification tag base configured to communicate with the controllerunit and configured to determine identification tags of consumable itemsused by the surfacing station, the controller unit being configured toenable a surfacing protocol for processing of the optical elements asworkpieces in function of an identified consumable item.
 19. Thesurfacing station according to claim 18, wherein an identification tagof the identification tags contains data about a type of the identifiedconsumable item.
 20. The surfacing station according to claim 19,wherein the identification tag contains data about lifetime and/orquantity of the identified consumable item.
 21. The surfacing stationaccording to claim 18, wherein an identification tag of theidentification tags is a RFID tag or a barcode tag or a matrix code tag.22. The surfacing station according to claim 18, wherein the surfacingstation is a polishing station, the processing protocol is a polishingprotocol, and the identified consumable item comprises at least oneconsumable item out of the following group of consumable items: apolishing disc of a polishing tool or a container of polishing slurry.23. The surfacing station according to claim 22, wherein the polishingstation comprises: a workpiece spindle, which projects into a work spaceand by way of which a workpiece to be polished is drivable for rotationabout a workpiece axis of rotation, two tool spindles, which areassociated with the workpiece spindle and project oppositely into thework space and are configured to support a respective polishing tooldrivable for rotation about a tool axis of rotation and axiallyadjustable along the tool axis of rotation, and the database containingat least one polishing protocol including a two-step polishing processwith different polishing medium carriers and at least one polishingprotocol including a one-step polishing process.
 24. The surfacingstation according to claim 18, further comprising a tag writerconfigured to write life-time data to an identification tag of theidentification tags, allowing re-use of the identified consumable itemif life-time of the identified consumable item has not expired.
 25. Thesurfacing station according to claim 18, wherein the controller unit isfurther configured to generate an output of enabled processing protocolsfor processing of optical elements as workpieces.
 26. The surfacingstation according to claim 18, wherein the database contains for atleast one specific job data a first two-step processing protocol and asecond one-step processing protocol of longer duration than the firsttwo-step processing protocol and leading to the same processing result,and the controller unit is further configured to switch from said firsttwo-step processing to said second one step processing in case the firsttwo-step processing protocol is disabled.
 27. A manufacturing facilityfor manufacturing of optical elements, comprising: several surfacingstations according to claim 18; a transfer system configured to conveyoptical elements to be processed according to specific job data; and amanagement system communicating with the controller units of thesurfacing stations and controlling the transfer system configured toconvey the optical elements to be processed, wherein the managementsystem is further configured to control the transfer system to conveyoptical elements to be processed according to the specific job data to asurfacing station where at least one enabled processing protocolcorresponds to specific job data of the optical elements to beprocessed.
 28. The manufacturing facility according to claim 27, whereinthe surfacing station is a polishing station, and wherein the managementsystem is configured to analyze a predetermined number of job data ofoptical elements to be processed, to determine an optimized polishingtool configuration of a pool of polishing stations, and to generate anoutput for exchange of polishing tools within the pool of polishingstations if the optimized polishing tool configuration differs from theworking polishing tool configuration.
 29. A polishing disc for apolishing tool for processing of surfaces of optical elements asworkpieces for a polishing station, comprising: a base body, which has acenter axis and to which is secured an intermediate layer, on which apolishing medium carrier rests, of a resilient material; and an RFID tagconfigured to be read by an identification tag base of the polishingstation and including a type of the polishing disc and life-time data,wherein the RFID tag is integrated in the base body of the polishingdisc on the center axis.
 30. A method for operating a surfacing stationfor processing of surfaces of optical elements as workpieces accordingto claim 18, comprising: determining information contained on anidentification tag of the identified consumable item; and enabling atleast one processing protocol for processing of the optical elements asworkpieces in function of the identified consumable item.
 31. The methodaccording to claim 30, wherein the identification tag is an RFID tag;and further comprising writing life-time data to the RFID tag allowingre-use of the identified consumable item if life-time of the identifiedconsumable item has not expired.
 32. The method for operating amanufacturing facility for manufacturing of optical elements accordingto claim 27, comprising: conveying optical elements to be processedaccording to specific job data to a surfacing station where the at leastone enabled processing protocol corresponds to the specific job data ofthe optical elements to be processed.
 33. The method according to claim32, wherein the surfacing stations are polishing stations; and furthercomprising: analyzing a predetermined number of job data of opticalelements to be processed, determining an optimized polishing toolconfiguration of a pool of polishing stations, and generating an outputfor exchange of polishing tools within the pool of polishing stations ifthe optimized polishing tool configuration differs from the workingpolishing tool configuration.
 34. The method according to claim 30,wherein the database contains for at least one specific job data a firsttwo-step processing protocol and a second one-step processing protocolof longer duration than the first two-step processing protocol andleading to the same processing result, and further comprising switchingfrom the first two-step processing to the second one-step processing incase the first two-step processing protocol is disabled.